基于小波降噪和短时傅里叶变换的主轴突加不平衡非平稳信号分析

针对主轴运行过程中突加不平衡而产生的非平稳信号无法采用传统的傅里叶变换对信号进行分析处理的问题，提出一种采用小波降噪与短时傅里叶变换相结合对主轴振动特征信息进行准确提取的方法，该方法利用小波降噪技术对非平稳信号进行滤波处理，再对滤波处理后的信号进行重构，最后通过短时傅里叶变换精确获取主轴振动幅值，通过仿真和实验验证了该方法的有效性。

Analysis of non-stationary signal of the sudden unbalanced spindle based on wavelet noise reduction and short-time Fourier transform

Since the response of a spindle with sudden unbalance shows non-stationary characteristics, it cannot be extracted by signal processing methods using traditional Fourier transform. To tackle this problem, a new signal extracting method combining wavelet de-noising technique and the short time Fourier transform method is proposed in this paper. Firstly, the non-stationary signal of the spindle is filtered and reconstructed by the wavelet de-noising technique. Then, the amplitude of the unbalance response is acquired by the short time Fourier transform method. Finally, the feasibility and the accurately of the proposed method is verified by numerical simulation and practical experiment.